HDMI not working on custom board

[baobabbob]

Hardware:
Orin nano module P3767-0003(with 256GB nvme) + customboard.

Custom borad status:

1. Modified form Orin nano dev kit, but changed DP to HDMI.
2. No EEPROM on it.

Jetpack:
5.1.3

My target:
Enable the HDMI output on custom borad.

Method:

1. I copied p3768-0000+p3767-0000.conf, named it p3768-0000+p3767-0000-zhou.conf, and modified two places:

   -PINMUX_CONFIG="tegra234-mb1-bct-pinmux-p3767-dp-a03.dtsi";
   -PMC_CONFIG="tegra234-mb1-bct-padvoltage-p3767-dp-a03.dtsi";
   +PINMUX_CONFIG="tegra234-mb1-bct-pinmux-p3767-hdmi-a03.dtsi";
   +PMC_CONFIG="tegra234-mb1-bct-padvoltage-p3767-hdmi-a03.dtsi";
   

2. Modify ./bootloader/t186ref/BCT/tegra234-mb2-bct-misc-p3767-0000.dts:

   cvb_eeprom_read_size = <0x0>;
   

3. Modify ./bootloader/t186ref/BCT/tegra234-mb2-bct-scr-p3767-0000.dts:

   +reg@322 { /* GPIO_M_SCR_00_0 */
   +          exclusion-info = <2>;
   +          value = <0x38009696>;
   +        };
   

4. Download kernel, then modify ./source/public/hardware/nvidia/platform/t23x/p3768/kernel-dts/tegra234-p3767-0000-p3768-0000-a0.dts.

   -#include "tegra234-dcb-p3767-0000-dp.dtsi"
   +#include "tegra234-dcb-p3767-0000-hdmi.dtsi"
   

5. Then build the kernel and apply new image\dtb according to Kernel customization.

Sucessed flash with command:

sudo ./tools/kernel_flash/l4t_initrd_flash.sh --external-device nvme0n1p1 -c tools/kernel_flash/flash_l4t_external.xml -p "-c bootloader/t186ref/cfg/flash_t234_qspi.xml" --showlogs --network usb0 p3768-0000+p3767-0000-zhou internal

host_log.txt (317.7 KB)

Issues:
Sadly no output on hdmi at all…

1.xrandr can query HDMI device, but when HDMI cable is plugged in or not, it aways shows disconnected.

xrandr --query -display :0.0

2.Tips for checking HPD is working, when HDMI cable is plugged in it shows ‘1’.

echo 424  > /sys/class/gpio/export
cat /sys/class/gpio/PM.00/value

So please help me.
Thanks!

By the way:

1. I can’t use p3509-a02+p3767-0000.conf for flashing, because my custom board nvme doesn’t fit for it.

[WayneWWW]

The gpio hotplug node is not added to device tree. Please check the display node under p3509 device tree and you will know what I am telling.

[baobabbob]

Decompile tegra234-p3767-0000-p3509-a02.dtb I can see “os_gpio_hotplug_a = <0x6 0x60 0x0>;”
Do you mean this?

[WayneWWW]

Yes, it means os_gpio_hotplug_a = <&gpio TEGRA234_MAIN_GPIO(M, 0) GPIO_ACTIVE_HIGH>;

[baobabbob]

Thanks, then how can this be achieved?

[WayneWWW]

achieve what…?

[baobabbob]

@WayneWWW

os_gpio_hotplug_a = <&gpio TEGRA234_MAIN_GPIO(M, 0) GPIO_ACTIVE_HIGH>;

Sorry for that reply, I mean how to patch “os_gpio_hotplug_a = <&gpio TEGRA234_MAIN_GPIO(M, 0) GPIO_ACTIVE_HIGH>;”?

[WayneWWW]

Add it to your device tree…

[baobabbob]

Do you mean this:

1. Decompile tegra234-p3767-0000-p3768-0000-a0.dtb, then add node “os_gpio_hotplug_a = <&gpio TEGRA234_MAIN_GPIO(M, 0) GPIO_ACTIVE_HIGH>;” under “display@13800000”?

[WayneWWW]

Add it to your source code… just as what you just did

Download kernel, then modify ./source/public/hardware/nvidia/platform/t23x/p3768/kernel-dts/tegra234-p3767-0000-p3768-0000-a0.dts.

[baobabbob]

Sorry, I am newbie to modifying the device tree. Anyway I will try the method you mentioned.